FIG. 1 shows a relay node (RN) 120 and user equipments (UEs) 131 and 132 present in an area of one eNodeB (eNB) 110 in a wireless communication system 100. The RN 120 may transmit data received from the eNB 110 to the UE 132 in an RN area and transmit data received from the UE 132 in the relay area to the eNB 110. The RN 120 may extend a high data rate region, enhance communication quality in a cell edge, and support provision of communication inside a building or to an area that exceeds an eNB service area. FIG. 1 shows the case in which there are a UE (hereinafter, referred to as Macro-UE or M-UE) that receives a service directly from an eNB, such as the UE 131, and a UE (hereinafter, referred to as Relay-UE or R-UE) that receives a service through the RN 120, such as the UE 132.
A radio link between the eNB 110 and the RN 120 is referred to as a backhaul link. A link to the RN 120 from the eNB 110 is referred to as a backhaul downlink and a link to the eNB 110 from the RN 120 is referred to as a backhaul uplink. In addition, a radio link between the RN 120 and the UE 132 is referred to as an access link. A link to the UE 132 from the RN 120 is referred to as an access downlink and a link to the RN 120 from the UE 132 is referred to as an access uplink.
When the RN 120 is operated using a method of controlling a cell by the RN 120 itself, the UE 132 may recognize the RN 120 as a general eNB. When another UE functions as the RN 120 (this relay node is referred to as a UE-relay), the UE 132 may not recognize presence of the RN 120.